Prime Minister Stephen Harper says he doesn't believe Israel deliberately attacked a United Nations post in southern Lebanon in a bombing that killed four UN observers, including a Canadian.

"I certainly doubt that to be the case," Harper said on Wednesday.

Maj. Paeta Derek Hess-von Kruedener, right, was one of the observers killed in a bomb shelter under a building marked as a UN post.
(CTV News/ Canadian Press)

Harper confirmed in a statement later that Canadian Forces member Maj. Paeta Derek Hess-von Kruedener, who was serving with the United Nations Truce Supervision Organization (UNTSO) mission in South Lebanon, was missing and presumed dead.

Hess-von Kruedener, from Kingston, Ont., was one of the observers killed in a bomb shelter under a building marked as a UN post. The other victims were from Austria, China and Finland. The body of Chinese UN observer Du Zhaoyu has been recovered and identified, China's Xinhua News Agency reported.

UN Secretary General Kofi Annan has suggested the post was deliberately targeted.

UN personnel carry the body of an unarmed UN military observer at a hospital in the southern Lebanese city of Marjayoun on Wednesday. The person was killed when a bomb struck a UN observer post.
(Lotfallah Daher/Associated Press)

But speaking to the media in New Brunswick, Canada's prime minister said he didn't believe that to be the case.

Harper pointed to the fact the government of Israel has been "co-operating with us in our evacuation efforts, in our efforts to move Canadian citizens out of Lebanon, and also trying to keep our own troops that are on the ground involved in the evacuation out of harm's way."

He said he wants to find out why the UN post was attacked, but also why "it remained manned during what is now, more or less, a war."

Israeli PM expresses 'deep regret'

Israeli Prime Minister Ehud Olmert has expressed "deep regret" over the bombing deaths of the four observers.

In a phone call to Annan, Olmert said there would be a full investigation.

However, Olmert expressed shock that Annan had called the bombing an "apparently deliberate" act by Israel.

"The prime minister said he could never fathom the thought that the mistake that was made would be categorized by the UN as an action that was done intentionally," said a statement from Olmert's office.

UN officials said Israel was warned repeatedly that its attacks were endangering lives of the UN peacekeeping force in Lebanon, known as UNIFIL, before the attack that killed the four peacekeepers.

According to a UN preliminary report, UN peacekeepers in southern Lebanon called the Israeli military 10 times in a six-hour period to ask it to halt bombing.

Annan has said Israel had given assurances to the UN that its positions would not be targeted by Israeli forces.
 
In a briefing note to the UN, Jane Lute, assistant secretary general for peacekeeping operations, said the IDF had been repeatedly firing too close to the patrol base on Tuesday.

She said 21 strikes occurred within 300 metres of the base and 12 artillery rounds fell within 100 metres of it, with four hitting the base directly.

The strikes occurred despite the fact "Hezbollah firing was not taking place within the immediate vicinity of the patrol base," she said.

Lute said that following the hit, Israeli troops continued to fire during the rescue operation and that incidents of firing close to UNIFIL positions were still happening Wednesday morning.

But Lute noted that UNIFIL has also come under direct attacks by small arms fire from Hezbollah.

The UN base has been in operation since 1972 and co-ordinates the organization's activities in southern Lebanon. Canada is not a member of UNIFIL, but did have eight personnel in the area as part of the UN Truce Supervision Organization.

Irish soldier reportedly warned Israelis to stop

Ireland's Foreign Ministry said Wednesday that a senior Irish soldier working in south Lebanon warned the Israelis six times that they were putting the lives of UN observers in danger with their air strikes.

"On six separate occasions, he was in contact with the Israelis to warn them that their bombardment was endangering the lives of UN staff in south Lebanon," said a spokesperson for Ireland's Department of Foreign Affairs.

"He warned, 'You have to address this problem or lives may be lost.'"

Ireland has filed an official protest with Israel. China has also demanded that Israel apologize for the attack.

Austria's foreign minister, Ursula Plassnik, told her Israeli counterpart by telephone that the bombing was unacceptable and urged Israel to stop its attack on the area.

Daniel Ayalon, Israel's ambassador to the U.S., called Annan's reaction "deplorable." He said the observers were caught in crossfire between Hezbollah and Israel.

Col. Roy Grottheim, a representative of the UN Truce Supervision Organization, said in a phone interview from Jerusalem that the observers killed were all mid-level officers who were unarmed. 

He told CBC News that they were taking refuge in the shelter when they were killed.

Grottheim said the UN has had a presence in south Lebanon since 1948 and the post had been there for several years.

"They are painted white with huge 'UN' letters written on different places. They have UN flags. It's quite clear where we have patrol bases," he said.

With files from the Associated Press and the Canadian Press